org.apache.hadoop.fs.http.server.HttpFSServerWebApp Maven / Gradle / Ivy
/**
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.hadoop.fs.http.server;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.CommonConfigurationKeysPublic;
import org.apache.hadoop.fs.http.server.metrics.HttpFSServerMetrics;
import org.apache.hadoop.lib.server.ServerException;
import org.apache.hadoop.lib.service.FileSystemAccess;
import org.apache.hadoop.lib.servlet.ServerWebApp;
import org.apache.hadoop.metrics2.lib.DefaultMetricsSystem;
import org.apache.hadoop.util.JvmPauseMonitor;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.IOException;
/**
* Bootstrap class that manages the initialization and destruction of the
* HttpFSServer server, it is a javax.servlet.ServletContextListener
* implementation that is wired in HttpFSServer's WAR
* WEB-INF/web.xml.
*
* It provides acces to the server context via the singleton {@link #get}.
*
* All the configuration is loaded from configuration properties prefixed
* with httpfs..
*/
@InterfaceAudience.Private
public class HttpFSServerWebApp extends ServerWebApp {
private static final Logger LOG =
LoggerFactory.getLogger(HttpFSServerWebApp.class);
/**
* Server name and prefix for all configuration properties.
*/
public static final String NAME = "httpfs";
/**
* Configuration property that defines HttpFSServer admin group.
*/
public static final String CONF_ADMIN_GROUP = "admin.group";
private static HttpFSServerWebApp SERVER;
private static HttpFSServerMetrics metrics;
private String adminGroup;
/**
* Default constructor.
*
* @throws IOException thrown if the home/conf/log/temp directory paths
* could not be resolved.
*/
public HttpFSServerWebApp() throws IOException {
super(NAME);
}
/**
* Constructor used for testing purposes.
*/
public HttpFSServerWebApp(String homeDir, String configDir, String logDir,
String tempDir, Configuration config) {
super(NAME, homeDir, configDir, logDir, tempDir, config);
}
/**
* Constructor used for testing purposes.
*/
public HttpFSServerWebApp(String homeDir, Configuration config) {
super(NAME, homeDir, config);
}
/**
* Initializes the HttpFSServer server, loads configuration and required
* services.
*
* @throws ServerException thrown if HttpFSServer server could not be
* initialized.
*/
@Override
public void init() throws ServerException {
if (SERVER != null) {
throw new RuntimeException("HttpFSServer server already initialized");
}
SERVER = this;
super.init();
adminGroup = getConfig().get(getPrefixedName(CONF_ADMIN_GROUP), "admin");
LOG.info("Connects to Namenode [{}]",
get().get(FileSystemAccess.class).getFileSystemConfiguration().
getTrimmed(CommonConfigurationKeysPublic.FS_DEFAULT_NAME_KEY));
setMetrics(getConfig());
}
/**
* Shutdowns all running services.
*/
@Override
public void destroy() {
SERVER = null;
if (metrics != null) {
metrics.shutdown();
}
super.destroy();
}
private static void setMetrics(Configuration config) {
LOG.info("Initializing HttpFSServerMetrics");
metrics = HttpFSServerMetrics.create(config, "HttpFSServer");
JvmPauseMonitor pauseMonitor = new JvmPauseMonitor();
pauseMonitor.init(config);
pauseMonitor.start();
metrics.getJvmMetrics().setPauseMonitor(pauseMonitor);
FSOperations.setBufferSize(config);
DefaultMetricsSystem.initialize("HttpFSServer");
}
/**
* Returns HttpFSServer server singleton, configuration and services are
* accessible through it.
*
* @return the HttpFSServer server singleton.
*/
public static HttpFSServerWebApp get() {
return SERVER;
}
/**
* gets the HttpFSServerMetrics instance.
* @return the HttpFSServerMetrics singleton.
*/
public static HttpFSServerMetrics getMetrics() {
return metrics;
}
/**
* Returns HttpFSServer admin group.
*
* @return httpfs admin group.
*/
public String getAdminGroup() {
return adminGroup;
}
}